The evolution of planet Earth and its biosphere are tightly linked through global biogeochemical cycles, and this dissertation seeks to explore this linkage during the Precambrian with new strategies and geochemical ...

I present a three-dimensional (3D) interpretation of long period magnetotelluric sites: 117 from 31 - 35 S and 37 from 35 - 38 S in western Argentina. The first field area covers the most horizontal part of the Pampean ...

The high power helicon (HPH) is a compact plasma source that can generate downstream densities of 10<super>17</super>-10<super>18</super> m<super>-3</super> and directed ion energies of 50-70 eV, without the need for grids ...

Despite recent advances in the study of pyroclastic density current (PDC) dynamics, several fundamental aspects of the behavior of these hazardous currents remain poorly understood. Perhaps two of the more significant gaps ...

Glacier erosion at convergent margins: a numerical and field study in the Chugach-St. Elias Mountains of South Alaska The Saint Elias range of South Alaska is known for its rapid erosion and uplift (order of 1 cm/yr), ...

Knowledge of hillslope erosion rates and processes is necessary for understanding landscape response to tectonic and climatic forcing and for determining the degree to which mountains regulate biogeochemical cycles and ...

Hydrated silica is found in a variety of Martian deposits within suites of minerals that indicate aqueous alteration, mostly because hydrated silica forms easily in different environments. Because of its relative ubiquity ...

Ice sheets play an important role in both the modern climate and in past variations of Earth's history. Our understanding of ice sheets has been limited by few observations until recent advances in technology, notably air ...

Glacier ice responds to environmental forcing through changes in its sliding speed and mass balance. While these changes often occur on daily time scales or longer, they are initiated by brittle deformation events that ...

The work contained in this thesis is focused on utilizing radiation transport code software as the basis for developing a well validated, first-principles model of global terrestrial cosmogenic nuclide production rates. ...

This study aims to better understand the series of events leading up to and following the Permian-Triassic mass extinction as it took place in the Panthalassic Ocean basin, with a particular focus on the oceanographic ...

Constraining the geometry of active faults is an important step in determining accurate estimates of regional seismic hazard. Where subsurface data are lacking, the shape of hanging wall folds can be used to interpret fault ...

The P-E boundary, approximately 56 Ma, coincides with a global climatic event, the Paleocene-Eocene Thermal Maximum (PETM). The PETM is believed to have resulted from a 2-8 fold increase in atmospheric pCO2 in less than ...

Sediment maturity, or the mineralogical and physical characterization of sediment deposits, has been used to locate of sediment source, transport medium and distance, weathering processes, and paleoenvironments on Earth. ...

Sediment maturity, or the mineralogical and physical characterization of sediment deposits, has been used to locate of sediment source, transport medium and distance, weathering processes, and paleoenvironments on Earth. ...

Geomagnetic storms result when energetic particles of solar and ionospheric origin fill Earth's inner magnetosphere and create a strong westward current, known as the ring current. This dissertation presents results from ...